The thing is that rhinoceroses aren't well-behaved. Even if some small fraction of them in theory might be well-behaved, the effort of trying to account for that is too small to bother. If 99% of rhinoceroses aren't well-behaved, the simple and correct response is to ban them all, and then maybe the nice ones can ask for a special permit. You switch from allow-by-default to block-by-default.

Similarly it doesn't make sense to talk about what happens if AI bots were well-behaved. If they are, then maybe that would be okay, but they aren't, so we're not talking about some theoretical (or past) situation where bots were well-behaved and scraped in a non-disruptive fashion. We're talking about the present reality in which there actually are enormous numbers of badly-behaved bots.

Incidentally, I see that in a lot of your responses on this thread you keep suggesting that people's problem is "not with AI" but with something else. But look at your comment that I initially replied to:

> Blocking AI training bots is not free and open for all.

We're not talking about "AI". We're talking about AI training bots. If people want to develop AI as a theoretical construct and train it on datasets they download separately in a non-disruptive way, great. (Well, actually it's still terrible, but for other reason. :-) ) But that's not what people are responding to in this thread. They're talking about AI training bots that scrape websites in a way that is objectively more harmful than previous generations of scrapers.